SYNTHESIS AND HYDROLYSIS OF OLIGODEOXYRIBONUCLEOTIDES CONTAINING 2-AMINOPURINE

A new method is reported for the synthesis of oligodeoxyribonucleotide s containing 2-aminopurine residues at selected sites. This method inv olves protection of the 2-aminopurine ribonucleoside, reduction to the deoxyribonucleoside and standard preparation of the -3'-O-(2-cyanoeth yl)-N,N-diisopropylphosphoramite. The 2-aminopurine phosphoramidite pr epared by this method couples with high efficiency and is stable under standard automated synthesis conditions. The presence and location of the 2-aminopurine residue is easily verified by treatment of the olig odeoxyribonucleotide with hot piperidine. The mechanism for selective hydrolysis of the 2-aminopurine residue in alkaline solution is predom inantly direct cleavage of the glycosidic bond.